What makes soda spew

Carbonated soda is essentially water containing dissolved carbon dioxide gas. During processing, the bottlers:. Thus, the pressure throughout the bottle is twice the pressure of the outside air, and, therefore, the pressure of the gaseous carbon dioxide in the neck of the capped bottle is at two atmospheres, as well.

This process results in a two-bottle volume of gaseous carbon dioxide in the bottle. More about this volume later. Gas molecules in the neck bop around at high speeds over kilometres an hour. Some hit the liquid below and enter the soda. Other gas molecules dissolved in the soda escape into the neck region. The concept of equilibrium.

Gradually, the rate at which gas molecules leave the neck and enter the soda equals the rate they leave the soda for the neck, and the soda is in equilibrium. The bottle achieves an equilibrium state after bottling and later on the shelf. How much carbon dioxide gas is in the bottle Henry's Law.

The bottle temperature is constant; the gas is in equilibrium and the bottle contains a given gas-soda combination - namely the bottled soda. So we can apply Henry's Law, which says that in this case, the amount concentration of dissolved gas in the soda is proportional to the pressure of the gas in the bottle's neck above the soda.

Since the neck gas pressure is double the atmospheric pressure, the bottle contains double the concentration of carbon dioxide gas as it would at one atmosphere - that is, two bottles of carbon dioxide gas. Why the capped, quiescent bottle has no bubbles. The bottle has been sitting on the shelf for some time. Gas It Up! Next, carbon dioxide gas is added to the soda mixture. Carbon dioxide gas will stay in the soda better if the soda mixture is cold. Fill 'Er Up!

Why does soda shoot out of the can when you open it? Why does soda bubble so much when you pour it on ice cream to make an ice cream soda? If the ice is already wet, some of the points are smoother so not as many bubbles form. Soda Pop Molecules.

Water A water molecule is made up of one oxygen atom and two hydrogen atoms. Sugar The sweetener in most soda is a mixture of a sugar called "glucose" and another called "fructose". Actually, the pressure hardly changes when the little bubbles shake loose and join the big bubble at the top.

Except for a small effect of surface tension, they take up the same volume either way. The cans and bottles are, of course, designed to be strong enough for the pressure.

Mike W. In your section called Soda Explosions! Was there a typo somewhere? Once the the can is opened, all of the gas will eventually escape from the liquid as bubbles, and the soda will go "flat. If the can is shaken, however, or if the liquid is poured quickly into a glass, then the bubbles formed by turbulence provide an easier way for the dissolved gas to escape.

It's difficult for the gas to escape from an undisturbed liquid because of the liquid's surface tension, which is the energy required to separate the liquid molecules from one another as a bubble forms.

For a tiny bubble just getting started, the amount of energy required per molecule of gas in the bubble is relatively large. So getting started is the difficult stage. Once it is formed, however, a smaller amount of energy again on a per molecule basis is needed for additional liquid molecules to vaporize and expand the bubble.